CHICAGO — Chicago Teachers Union is set announce its strike date Wednesday. If contract negotiations fail, CTU and its 25,000 members could strike this month. On Tuesday morning, members of SEIU Local 73 delivered strike notices to City Hall. Its members include 7,500 Chicago Public School support staff and 2,500 park district employees. They are prepared to strike at the same time as CTU, which means nearly 35,000 city employees could hit the picket line at the same time. Mayor Lori Lightfoot inherited a teachers union contract negotiation already in progress. Since taking office in May, though, progress isn’t what’s occurred at the bargaining table, despite the city agreeing to a teachers pay increase of 16 percent over 5 years. “We have our own substantive offers that have gone unanswered for weeks and going on months,” she said. CTU wants written guarantees over a living wage for teachers aides and adequate staffing for other support staff, including social workers, nurses, case managers and librarians. Classroom size is also an issue. CTU said thousands of classrooms are overcrowded and are calling for an enforceable cap written into the contract. Lightfoot said she wants a deal and added positions into the budget, not the contract. She said she’s waiting for a counteroffer, which hasn’t happened. Also Tuesday, the city launched a website to highlight the district deal already on the table. The site cps.edu/ouroffer outlines the current proposal, which includes a 16% pay raise over five years and a commitment to hire more support staff such as social workers and nurses. The union also established a website laying out their issues, in-depth.